// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package ethapi

import (
	"fmt"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/rpc"
)

type TxPool interface {
	Stats() (pending int, queued int)
	Content() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)
}

// TxPoolDebugAPI offers and API for the transaction pool. It only operates on data that
// is non confidential.
type TxPoolDebugAPI struct{ Pool TxPool }

// Content returns the transactions contained within the transaction pool.
func (s TxPoolDebugAPI) Content() map[string]map[string]map[string]*RPCTransaction {
	content := map[string]map[string]map[string]*RPCTransaction{
		"pending": make(map[string]map[string]*RPCTransaction),
		"queued":  make(map[string]map[string]*RPCTransaction),
	}
	pending, queue := s.Pool.Content()

	// Flatten the pending transactions
	for account, txs := range pending {
		dump := make(map[string]*RPCTransaction)
		for nonce, tx := range txs {
			dump[fmt.Sprintf("%d", nonce)] = newRPCTransaction(tx)
		}
		content["pending"][account.Hex()] = dump
	}
	// Flatten the queued transactions
	for account, txs := range queue {
		dump := make(map[string]*RPCTransaction)
		for nonce, tx := range txs {
			dump[fmt.Sprintf("%d", nonce)] = newRPCTransaction(tx)
		}
		content["queued"][account.Hex()] = dump
	}
	return content
}

// Status returns the number of pending and queued transaction in the pool.
func (s TxPoolDebugAPI) Status() map[string]*rpc.HexNumber {
	pending, queue := s.Pool.Stats()
	return map[string]*rpc.HexNumber{
		"pending": rpc.NewHexNumber(pending),
		"queued":  rpc.NewHexNumber(queue),
	}
}

// Inspect retrieves the content of the transaction pool and flattens it into an
// easily inspectable list.
func (s TxPoolDebugAPI) Inspect() map[string]map[string]map[string]string {
	content := map[string]map[string]map[string]string{
		"pending": make(map[string]map[string]string),
		"queued":  make(map[string]map[string]string),
	}
	pending, queue := s.Pool.Content()

	// Define a formatter to flatten a transaction into a string
	var format = func(tx *types.Transaction) string {
		if to := tx.To(); to != nil {
			return fmt.Sprintf("%s: %v wei + %v × %v gas", tx.To().Hex(), tx.Value(), tx.Gas(), tx.GasPrice())
		}
		return fmt.Sprintf("contract creation: %v wei + %v × %v gas", tx.Value(), tx.Gas(), tx.GasPrice())
	}
	// Flatten the pending transactions
	for account, txs := range pending {
		dump := make(map[string]string)
		for nonce, tx := range txs {
			dump[fmt.Sprintf("%d", nonce)] = format(tx)
		}
		content["pending"][account.Hex()] = dump
	}
	// Flatten the queued transactions
	for account, txs := range queue {
		dump := make(map[string]string)
		for nonce, tx := range txs {
			dump[fmt.Sprintf("%d", nonce)] = format(tx)
		}
		content["queued"][account.Hex()] = dump
	}
	return content
}